PoolingClientConnectionManagerMBeanInstaller.java

/**
 * Sonatype Nexus (TM) Open Source Version
 * Copyright (c) 2007-2012 Sonatype, Inc.
 * All rights reserved. Includes the third-party code listed at http://links.sonatype.com/products/nexus/oss/attributions.
 *
 * This program and the accompanying materials are made available under the terms of the Eclipse Public License Version 1.0,
 * which accompanies this distribution and is available at http://www.eclipse.org/legal/epl-v10.html.
 *
 * Sonatype Nexus (TM) Professional Version is available from Sonatype, Inc. "Sonatype" and "Sonatype Nexus" are trademarks
 * of Sonatype, Inc. Apache Maven is a trademark of the Apache Software Foundation. M2eclipse is a trademark of the
 * Eclipse Foundation. All other trademarks are the property of their respective owners.
 */
package org.sonatype.nexus.apachehttpclient;

import java.lang.management.ManagementFactory;
import javax.inject.Named;
import javax.inject.Singleton;
import javax.management.MBeanServer;
import javax.management.ObjectName;

import org.apache.http.client.HttpClient;
import org.apache.http.impl.conn.PoolingClientConnectionManager;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * An wrapper {@link Hc4Provider} that automatically registers / unregisters JMX MBeans for each created
 * {@link HttpClient}s and {@link PoolingClientConnectionManager}.
 *
 * @since 2.2
 */
@Named()
@Singleton
public class PoolingClientConnectionManagerMBeanInstaller
{

    private static final Logger LOGGER = LoggerFactory.getLogger( PoolingClientConnectionManagerMBeanInstaller.class );

    private static final String JMX_DOMAIN = "org.sonatype.nexus.httpclient";

    private ObjectName jmxName;

    public synchronized void register( final PoolingClientConnectionManager connectionManager )
    {
        if ( jmxName == null )
        {
            try
            {
                jmxName = ObjectName.getInstance(
                    JMX_DOMAIN, "name", PoolingClientConnectionManager.class.getSimpleName()
                );

                final MBeanServer server = ManagementFactory.getPlatformMBeanServer();
                server.registerMBean( new PoolingClientConnectionManagerMBeanImpl( connectionManager ), jmxName );
            }
            catch ( final Exception e )
            {
                LOGGER.warn(
                    "Failed to register mbean {} due to {}:{}",
                    new Object[]{ jmxName, e.getClass(), e.getMessage() }
                );
                jmxName = null;
            }
        }
        else
        {
            LOGGER.warn( "Already registered mbean {}", jmxName );
        }
    }

    public synchronized void unregister()
    {
        if ( jmxName != null )
        {
            try
            {
                final MBeanServer server = ManagementFactory.getPlatformMBeanServer();
                server.unregisterMBean( jmxName );
            }
            catch ( final Exception e )
            {
                LOGGER.warn(
                    "Failed to unregister mbean {} due to {}:{}",
                    new Object[]{ jmxName, e.getClass(), e.getMessage() }
                );
            }
            finally
            {
                jmxName = null;
            }
        }
    }

}